Apparatus for electrocoating striplike material



Oct. 2, 1951 E. w. RIEGER 2,569,578

APPARATUS 'FOR ELECTROCOATING STRIP-LIKE MATERIAL Fil Aug. 7. 1944 3 Sheets-Sheet l 0d. 2, 1951 E, w. RlEGER 2,569,579

APPARATUS FOR ELECTROCOATING STRIP-LIKE: MATERIAL Filed Auz- 7. 1944 :s sheets-sheet 2 APPARATUS Foa ELECTROCOATING STRIP-LIKE MATERIAL Filed Aug. 7, 1944 'i E. W. RIEGER Oct. 2, 1951 3 Sheets-Shasta 3 gef INVENTOR. Em es h( Rie "IIIIIIIIIIIIIIII IIIIIIIIIIIIIII..

Patented Oct. 2, 1951 APPARATUS FOR ELECTROCATING STRIPLKE MATERIAL Ernest w. Rieger, weirum, W. vavasysignpr to National Steel Corporation, a corporation of Delaware Application August 7, 1944, Serial No. 548,406

6 Claims.

The present invention relates to the electrocoating of stripelike material, and more particularly to the coating line where the electro-deposited metal is applied to the base material. My invention is particularly applicable to the manufacture oi tinplate by the electrolytic process and will be so described herein. However, it will readily apparent to those skilled in this art that my invention may be applied in the electro-galvanizing of strip or in `other processes wherein a base metal is coated with another metal by an electro-deposition process.

Several different processes of manufacturing tinplate by the electrolytic method have been employed heretofore. I-n one process employed commercially the strip is continuously*` fed through a bath in which bars of tin are suspended, the strip being passed vertically upwardly and then downwardly past the tin bars which form the anodes of the electric circuit. In this process the strip is simultaneously coated with tin on both sides. In another process which has been used heretofore commercially, the strip is passed con'- tinuously through one series of tanks or cells containing the tin anode bars and the strip coated on one side only. In this process, the strip is then passed through a second series of plating cells in which the other side is similarly coated. My invention is particularly applicable to this latter process, due to the fact that there is an appreciably greater amount of the electrolyte -carried from the plating cells by the strip in this process than in the process in which the strip is passed vertically upwardly and downwardly in the bath and simultaneously coated on both sides. However the principles of my invention are applicable to and may be employed in either type of process.

In the .process in which the strip is coated first on one side and then on the other side, the strip passes successively through a series of plating tanks or cells. Each plating cell has in it a plurality of tin anode bars which are immersed in the electrolyte. The strip passes through each cell above the anode bars and substantial-ly at but nevertheless slightly below the surface of the electrolyte bath contained in the cell. The strip forms the cathode of the electric circuit and passes between a contact roll and a backing roll on the strip entry end of each cell.

Due to the fact that the electrolyte must come in contact with the strip as it passes through each cell, there is a constant out-dow of the electrolyte from the cell regardless of the speed at which the strip passes therethrough. Some circulation Lil) (Cl. ZIM- 206) of the electrolyte from the cells to a storage tanlc and from the storage tank back to the cells is desirable in order to obtain uniformity in the deposition of the tin on the strip` However as will be pointed out hereinafter, excessive circulation is highly undesirable for various reasons. i

The strip, in normal operations, passes through the plating cells at a relatively high rate o l speed. The speeds normally employed are in the neighborhood of 590 to 1900 or more feet per minute. Where such speeds are employed lthe strip, due to its forward motion, drags or carries with it aAsubstantial amount of the electrolyte and causes it to discharge from each cell at the strip discharge end thereof. The strip discharge end of each cell is normally open from a point below the `.surface of the electrolyte bath and consequentl'y there is normally some ow of the electrolyte from the tank atthis point. However, where speeds such as those mentioned above are employed, this normal spillage is supplemented by the amount dragged forward by the strip and is objectionably large for several reasons. The discharged electrolyte is deposited in trays positioned below the cells and from each 'tray it is carried to the storage tank for recirculation through the cells.

It has been the practice heretofore to allow the electrolyte to flow over the sides of each plating cell and also over the strip 'entry end as well as over the strip discharge end. Due to the 'substantial nature of this 4spillage an extremely li'igh pumping rate has been required in order to main# tain fa proper amount ci Vthe electrolyte iii-each ceu. where a high cireuiation rate is requiredfss a result of the substantial spillage of the ele'e trolyte from leach cell, objectionable aeration oi the electrolyte is encountered. The aeration of the electrolyte results in the conversion of stan# nous chloride in the electrolyte to the relatively insoluable stanhic chloride. As a consequence, a sludge is formed in the plating cells and in the storage tank and recirculating apparatus. Where a high degree of aeration :is encountered, a high rate ci sludge formation is likewise encountered'. Tests haveshown that the rate of sludge formation is substantially directly proportional to the pumping rate required to replenish the electrolyte discharged from the cells by spillage.

Aeration of the electrolyte is caused by several diierent factors. Where the strip pulls the e1ectrolyte from the cells at; a relatively high rate, the discharged electrolyte strikes the liquid sur-1 face in the tray positioned below the cells and considerable aeration takes place at this point.

'This electrolyte is discharged from the trays through conduits and at the point where the electrolyte enters each conduit there is a substantial amount of turbulence which results in aeration of the liquid. Some of the electrolyte is discharged over the sides of the cells and if this discharge is at a relatively low rate and the liquid falls into the trays in the form of a film, only a small amount oi aeration takes place. However, frequently the liquid cascades downwardly over the sides of the cells and an appreciable amount of aeration takes place. This is particularly true adjacent the strip discharge end of each cell.

In accordance with the present invention I provide apparatus appreciably reducing the aeration of the electrolyte and the pumping rate required to keep the cells supplied with the electrolyte. In the apparatus which I provide discharge of the `electrolyte over the sides or each cell is eliminated as the sides extend upwardly from the bottom wall to above the level of the electrolyte under normal operating conditions. The flow of the electrolyte from each cell is in a direction opposite to the direction of travel of the strip and is discharged over an end wall or weir at the strip entry end of the cell. The body of the electrolyte has a quiescent level above the plane of the strip when the strip is stationary during nonoperating periods. This quiescent level is also above the end wall or weir at the entry end of the cell or tank. The electrolyte is dragged along in the direction of travel of the strip by the strip during operating periods and in order to prevent discharge of any substantial amount of the electrolyte from the strip dischargp end of the tank a. dam is provided. The dam `includes an electrical current strip contact roll and a pressure roll which is utilized to press the strip into engagement with the Contact roll. The roll pass formed by the rolls is in substantially the same horizontal plane as that in which the strip lies during its passage through the tank. This plane, as is stated above, is below the quiescent level oi the electrolyte. The dam also includes sealing means extending between the walls of the tank or cell at the discharge end and the rolls and in thismanner any substantial discharge of electrolyte at the discharge end of the cell is eliminated.

With this arrangement electrolyte is discharged from each cell only at the strip entry end, except for the small amount of leakage which will normally take place at the strip discharge end. However, the amount discharged at the strip entry end is only a small fraction of that discharged from each cell in the presently known types of apparatus and, as a consequence, aeration of the electrolyte is minimized. the pumping rate required to keep the proper amount of electrolyte in each cell is reduced and the sludgeforming rate is also reduced. Thus substantial savings in operating costs are effected.

In the accompanying drawings, I have shown, for purposes of illustration only, a preferred embodiment of my invention. In the drawings,

Figure 1 is a plan view of a portion of an electro-coating line embodying my invention;

Figure 2 is a central, vertical longitudinal section through the apparatus shown in Figure 1;

Figure 3 is a transverse vertical section taken along the line III-III of Figure 1;

. Figure 4 is a plan view of a portion of the apparatus shown in Figure 1 adjacent the strip discharge end of the cell;

Figure 5 is an enlarged sectional view showing a portion of the apparatus adjacent the strip dis-l charge end of the cell; and

Figure 6 is'a partial sectional view taken along the line VI-VI of Figure 4.

In the apparatus shown in the drawings. the strip S passes from the immediately preceding cell or, in the case of the first cell in the line. from the pretreating apparatus between a pair of rolls comprising a contact roll 2 and a backing roll 3. These rolls are positioned at the strip entry end of the initial cell in the line and are positioned between each of the cells in the line. The contact roll 2 is provided with necks 4 which cooperate with electrical apparatus (not shown) forming a part of the electrical circuit. The roll Il is merely a backing roll and is ordinarily formed of hard rubber. y i

After the strip passes between the rolls 2 and 3, it passes into the plating cell which is indicated generally by the reference character 5. The cell 5 contains a plurality of anode bars 6 of tin. One end of each anode bar is supported on an insulated member l and the other end is supported on a carbon block 8 which forms apart of the electrical circuit. The carbon block, at one side of the cell, is provided with bars 9 which are connected to electrical apparatus for supplying current to the system. The cell 5 contains the electrolyte bath, the level of which is normally slightly above the level of the strip. The electrolyte is fed to the cell either by a conduit opening through the bottom of the cell or by a pipe or hose 40 (Fig. 3) located above the strip level and arranged to discharge the electrolyte onto the surface of the strip, or in both ways. I have found that it is desirable to supply the electrolyte in the latter way because it results in covering the top surface of the strip with the electrolyte. If this is not done, the tinning of the top surface in later operations is not uniform.

As the strip passes through the cell, tin is deposited from the anode bars 6 onto the strip. The strip passes from the cell at the end opposite the entry end and passes between the contact roll 2 and the backing roll 3 adjacent the strip entry end of the next succeeding cell.

Reference is hereby made to the copending application of Clarence J. Klein, Serial No. 523,- 681, led February 24, 1944. now Patent Number 2,509,304. for a more complete description of a tinning line of the general type described above.

As stated above, the strip carries a substantial portion of the electrolyte forwardly through the cell. and, in the absence of means for preventing it the electrolyte ows over the end wall I0 at the strip discharge end of the cell and is deposited in a tray Il which extends beneath the discharge end of one cell and the entry end of the next succeeding cell. Also some of the electrolyte is normally withdrawn from the cell at the discharge end thereof through downcomers l2 which discharge the electrolyte into the tray Il.

In accordance with my invention, provision is made to substantially eliminate the discharge of the electrolyte over the end wall Ill of the cell and over the side Walls 2|. The end wall IIJ has a horizontal portion I3 which carries an extension member I4 which partially bridges the area between the end wall of the cell and the backing roll 3. The extension Il comprises a top plate l5 and a bottom plate I6 and a supporting member I1, all of which are either covered with a heavy layer of rubber or some other material which is resistant to the action oi the eleci trelyte or painted-Witwe thin ecmftingwetrubberJ or-someother similar material.-

vThe Aextension M- does net-completely bridge the space-betweentheend wall M end-the -bdelb ing rulli. However the extension-carries-sa re e silient bridging member-la which extends Iorwardly into contact withl the-backing roll. *Fiiisf resilient bridging member isfpreierablymade -cfi good quality natural vor synthetic rubber which will resist the action o f the elecrolyte andwhichmi.

will withstandfthe wear of the rotatingrolll3;` The extension `I4 andthe resilient'bridgingmember I8-completely bridge jthe area Alrom the 'end` wall'm'to the backing roll31so that electrolytei cannot iiow downwardlyA over vthe endY wall into- 151.

the. collecting tray iN.'

In .order to prevent the electrolyte from vflowiusridewise edleeent the rolls 2 ,and 3; sidepletes ormembers Illere previsled .Eeeh' eisleiplate 2]) copstitutesan extension of a side wallzl q1- 120itrieeell. Eachslderletellihesen arm 2 2 which. extends generally parallel te .the-plete :end Lie.` joined to the plete to forme Seetlenttirispver the en d of the adjacent side wall oi vthe cell;

The plate 2U, the arm 22'and theslde welll! Commcdate the neckspf the rclls. The fx'ont end of ,each plate Zllpreferably extends to orY slightly beyondtheaxis of ythe rolia IHieretofore in electrotinnlnglnes of the chars acte): illustrated in the drawingsiI thesides 2L oi eachcell extended upwardly slightly aboye, the swallsat the strip entry and,discharge eri|;l s` As ,a ,consequence, considerableV spillage stock., place over the side walls near the nxit endend: troughs were provided forY colleptingxhisspille, age. In accordance .withmy invention the Sides. il are extended upwardlyfbeyondfthe end wall at the strip entry end andfof ,ceursehighgp than the Aend` well l0 ,et the sirindieehercesndr of the cell. At thelstrip entry .end Vclaefside-wang are., sufficiently high to preclude any spillage ,011., the. electrolyte thereover. At Atllefother engifoi thetcell `thesewalls must somewhat higherf, inyleyv of the fact that the stcippulls ,theelece trglyte ytlfiroughtlfie cell and causes 4itto -p i1e,pp

teen appreciable extentaheadci' lthe rolls Landi 5gY 3., The side wal1s 2 l need no t entend vertically delle :es flflieh` ee the extension Side platee 20de, view ofl the -fact that the ,electrolyte buildfup is, highest immediately in -frentef therclle;

The Side wells .2L the Sldemletesfllbithe erece tension member |4,V and the -i:esi lientbiiiclgitig member IB -prevent sidewiee spillage ,ef theieleef trente end elee .prevent-any silbeiielillfiely ernennt o f the electrolyte from being discl'iargegfiropp the strip dleeheree end 0l the cellinteeineril,l The Side platee :20 end members I4 and ,I- ce@ Operate-With rolls 2 and '3 t0. -felfinintellectlel dem preventing the dressingy ofV cles,trelytetnerebeyend- Of course. :ell leakage et: this eiidv ci :theeell cannot be prevented inwlew `or fthe: se

feci -fthet -leeknroet icinte .cannot pbe, provided between eide plates 2B and theneeks ofthe nella 2 end 3 ibut athis leelsege extremely fsmciltnnw lsfof nc ,conseeuencewhesc the apparatus Just; deexibedisempleyed.

YIn viewer/thelfactrthat,spillage over theestripf discharge end of :the cell is prevented and in viewer fthe fact that sidewise spillage is prevented, the electrolyte ilows rearwardly through theeellranddisdischarged,over the end wall 2,5. The end wall 25 is in 'theeshapefof` an inverted U. the oneJleg-of. the U extendingdownwardlylto a short-distance above thebottom of the. tray I0 so lthat therewill bea-minimum amount of aeration oflthe-electrolyte-at this point. If thelelec` trolyte were permitted to spill into the tray I0 from-approximately `the `strip level considerableA aeration'would -take place at this point.

Where'the apparatus just described is employec'l,r itis riotiiecessaryzand4 in mostcases i it is undesirable, to withdraw any portion of the electrolyte from the cell through the downcomers i2; As a consequence thesedowncomers are normally clQSed by plug valves 2B `in. normal operations. However if desired ,a small amount of the electrolyte may be continuously withdrawn from the celllthrough'these downcomers.

Asstated above, where apparatus of the charactel' just described is employed, aeration is re- 'V ducedtoa minimum, the pumping rate is reduced toj a, srnall fraction of what would be required withoutmy improvements and sludge formation is vreduced appreciably. As a consequence. oper,-

ating costs are materially reduced and a more efficient, high speed tinning line is provided.

While I have shown and described a preferred embodiment of my invention, it will be understood that invention is not :limited thereto but may j beotherwiseembodied within the scope of the ap Dendedclaims.

I claim:

1. ,In .apparatus for lprogressively electroplat-A in g strip, the combination comprising, a tank f orhcldirigafbathof electroplating solution, means for. moving the strip along a horizontal path across the tank from the entry end to the exit end whereby the moving strip drags electroplatimg solutiontin thedireetion of striptravel, means for-supplyingelectroplating solution to the tank, an e1 e0 ter oplating anode disposed in said tankV belpw .thegpeth of the strip, said tank having a bottom Weill. side walls extending upwardly from theY bottom wall above the path of the strip adress theltank `for preventing spillage of electroplating solution across the side Walls,Y an entry end Wa-11, extending upwardly from the bottom` walltoward the path of the strip and terminatingbelbw the path of -the strip and below the side walls., Said tank 4being free of means preventing the spillage of solution across the top of the entry endweill end sald entry .end walllforming adischargelweir, for thesolution at theentrance end of1the -;tank, and an exitend wall at theexit end ofthe tank extending upwardly from the bottom wall toward the-path of the strip, said strip moving means .comprising a., pair of strip engaging. rolls 1includingan upper roll .and a lower roll adjaeent ;the discharge end of and positioned outside of Ythe tank, one .of said rolls being a, contact roll for` making electrical-contact with the strip, means for connecting the contact roll and the; anodey to a. sourceof. electric current, sealing, means extending between Yeach .of the side walls offitheftanklandthe rolls and sealing means ex,- tending `between Vat least one of `the rolls and the exit end walliof pthe. tank, the sealing means with the rolls `preventing `the spillage oi' electroplating. solution immthe exit end of the tank soy that substantially all' of .the Aspillage .of electroplatingl for moving the strip along a horizontal pathl across the tank from the entry end to the exit end whereby the moving strip drags electroplating solution in the direction of strip travel, means for supplying electroplating solution to the tank, an electroplating anode disposed in said tank below the path of the strip, said tank having a bottom wall, side walls extending upwardly from the bottom wall above the path of the strip acrossl the tank for preventing spillage of electroplating` solution across the side walls, an entry end wall extending upwardly from the bottom wall towardA the path of the strip and terminating-below the path of the strip and below the side walls, said tank being free of means preventing the spillage of solution across the top of the entry end wall and said entry end wall forming a discharge Weir for the solution at the entrance end of the tank, and an exit end wall at the exit end of the tank extending upwardly from the bottom wall toward the path of the strip, said strip moving means comprising a pair of strip engaging rolls including an upper roll and a lower roll adjacent the discharge end of and positioned outside of the tank, one of said rolls being a contact roll for making electrical contact with the strip and each of said rolls having at each end a relatively smaller roll neck, means for connecting the contact roll and the anode to a source of electric current, a side wall extension for each Vside wall and having demountable sealing connection therewith and extending forwardly to the lower roll and being cut away at the forward end to engage the periphery of the corresponding roll neck of the' lower roll, and sealing 'means extending from the said exit end wall of the tank to said lower roll which together with said side wall extensions form a, container for holding the plating solution and for restraining the spillage of electroplating solution from the exit end of the' tank so that substantially all of the spillage of electroplating solution from the tank is across the entry end wall in a direction countercurrent to the directionof strip movement across the tank, and meansextending beneath the entry end of the tank for collecting the electroplating solution spilling over the entry end wall of the tank.

3. In apparatus for progressively electroplating strip, the combination comprising, a tank for holding a bath of electroplating solution, means for moving the strip along a horizontal path across the tank from the entry end to the exit end whereby the moving str-ip drags electroplat.

ing solution in the direction of strip travel, means for supplying electrcplating solution to the tank, an electroplating anode disposed in said tank below the path of the strip, said tank having a bottom wall, side walls extending upwardly from the 4bottom wall above the path of the strip across the tank for preventing spillage of electroplating solution across the side walls, an entry end wall extending upwardly from th-e bottom wall toward the path of the strip and terminating below the path of the strip and -below the side walls,

said tank being free of means preventing the.

end wall and said entry end wall forming a dis--I charge Weir for the solution at the entrance end of the tank, and an exit end wall at the exit end of the tank extending upwardly from the bottom wall toward the path of the strip, said strip moving means comprising a pair of strip engaging rolls including an upper roll and a lower roll adjacent the discharge end of and positioned outside of the tank, one of said rolls being a contact roll for making electrical contact with the, strip and each oi said rolls having at each end4 a relatively smaller roll neck, means for con-l necting the contact roll and the anode to a sourceoi' electric current, a. side wall extension for each? side wall and having demountable sealing connection therewith and extending forwardly into engagement with the ends oi' the rolls and being" cut away at the forward end to engage the peripheryof the corresponding roll necks with `a portion at the forward end extending between the roll necks, and a sealing means extending' from the said exit end Wall of the tank to saidI lower roll which together with said side wall extensions form a container for holding the plat' ing solution and for restraining the spillage of electroplating solution from the exit end of the tank so that substantially all of the spillage of electroplating solution from the tank is across the entry end wall in a direction countercurrent to' the direction of strip movement across the tank,f and means extending beneath the entry end of' the tank for collecting the electroplating solution'l spilling over the entry end wall of the tank.

4. In apparatus for progressively electroplat`l ingstrip, the combination comprising, a tank for holding a bath of electroplatlng solution, meansj for moving the strip along a horizontal pathl `across the tank from the entry end to the exitend whereby the moving strip drags electroplating solution in the direction of strip travel.

means for supplying electroplating solution to the tank. an electroplating anode disposed in said tank below the path of the strip, said tanl':

venting the spillage of solution across the top" of the entry end wall and said entry end wall forming a discharge weir for the solution at theentrance end of the tank, and an exit end wall at the exit end of the tank extending upwardlyv from the bottom wall toward the path of the strip, said strip moving means comprising a pairi of strip engaging rolls including an upper roll" and a lower roll adjacent the discharge end of and positioned outside of the tank, one of said rolls being a contact roll for making electrical contact with the strip, means for connecting the` contact roll and the anode to a source of electric current. a side wall extension for each side wall, each side wall extension including a member extending from the side wall forwardly t0- the lower roll and a parallel arm spaced from and joined at one end to the member, the mem--V ber and arm fitting over the end of the corresponding side wall and forming a. demountable connection therewith, and a sealing means extending from the exit end wall to said lower rollA which together with said side wall extensions of the tank form a container for holding the.

spillage of solution across the top of the entry plating solution and for restraining the spillage of electroplating solution from the exit end of the tank so that substantially all of the spillage of electroplating solution from the tank is across the entry end wall in a direction countercurrent to the direction of strip movement across the tank, and means extending beneath the entry end of the tank for collecting the electroplating solution spilling over the entry end wall of the tank.

5. In apparatus for progressively electroplating strip, the combination comprising, a tank for holding a bath of electroplating solution, means for moving the strip along a horizontal path across the tank from the entry end to the exit end whereby the moving strip drags electroplating solution in the direction of strip travel, means for supplying electroplating solution to the tank, an electroplating anode disposed in said tank below the path of the strip, said tank having a bottom Wall, side Walls extending upwardly from the bottom wall above the path of the strip across the tank for preventing spillage of electroplating solution across the side walls, an entry end wall extending upwardly from the bottom wall toward the path of the strip and terminating below g the path of the strip and below the side walls, said tank being free of means preventing the spillage of solution across the top of the entry end wall and said entry end wall forming a discharge Weir for the solution at the entrance end of the tank, and an exit end wall at the exit end of the tank extending upwardly from the bottom wall toward the path of the strip, said strip moving means comprising a pair of strip engaging rolls including an upper roll and a lower roll adjacent the discharge end of and positioned outside of the tank, one of said rolls being a contact roll for making electrical contact with the strip, means for connecting the contact roll and the anode to a source of electric current, a side wall extension for each side wall, each side Wall extension including a member extending from the side wall forwardly to and into engagement with the rolls and a parallel arm spaced from and joined at one end to the member, the member and arm fitting over the end of the corresponding side wall and forming a demountable connection therewith, and a sealing means extending from the exit end wall to said lower roll which together with said side wall extensions of the tank form a container for holding the plating solution and for restraining the spillage of electroplating solution from the exit end of the tank so that substantially all of the spillage of electroplating solution from the tank is across the entry end wall in a direction countercurrent to the direction of strip movement across the tank, and means extending beneath the entry end of the tank for collecting the electroplating solution spilling over the entry end wall of the tank.

6. In apparatus for progressively electroplating strip, the combination comprising, a tank for holding a bath of electroplating solution, means for moving the strip along a horizontal path across the tank from the entry end to the exit end whereby the moving strip drags electroplating solution in the direction of strip travel, means for supplying electroplating solution to the tank, an electroplating anode disposed in said tank below the path of the strip, said tank having a bottom wall, side walls extending upwardly from the bottom Wall above the path of the strip across the tank for preventing spillage of electroplating solution across the side walls, an entry end wall extending upwardly from the bottom wall toward the path of the strip and terminating below the path of the strip and below the side walls, said tank being free of means preventing the spillage of solution across the top of the entry end wall and said entry end Wall forming a discharge Weir for the solution at the entrance end of the tank, and an exit end wallat the exit end of the tank extending upwardly from the bottom wall toward the path of the strip, said strip moving means comprising a pair of strip engaging rolls including an upper roll and a lower roll adjacent the discharge end of and positioned outside of the tank, one of said rolls being a contact roll for making electrical contact with the strip and each of said rolls having at each end a relatively smaller roll neck, means for connecting the contact roll and the anode to a source of electric current, a side wall extension for each side wall, each side wall extension including a member extending from the side wall forwardly to and into engagement with the ends of the rolls and being cut away at the forward end to engage the periphery of the corresponding roll necks with a portion at the forward end extending between the roll necks, and a parallel arm spaced from and joined at one end to the member. the member and arm tting over the end of the corresponding side wall and forming a demountable connection therewith, and a sealing means extending from the exit end wall to said lower roll which together with said side wall extensions of the tank form a container for holding plating solution and for restraining the spillage o1 electroplating solution from the exit end of the tank so that substantially all 0f the spillage of electroplating solution from the tank is across the entry end wall in a direction countercurrent to the direction of strip movement across the tank, and means extending beneath the entry end oi' the tank for collecting the electroplating solution spilling over the entry end wall of the tank.

ERNEST W. RIEGER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,191,336 Battle July 18, 1916 1,242,695 Hood Oct. 9, 1917 1,484,653 Kirschner Feb. 26, 1924 2,024,248 Rafton Dec. 17, 1935 2,093,238 Domm Sept, 14, 1937 2,271,736 Hall Feb. 3, 1942 2,307,928 Hogaboom Jan. 12, 1943 2,324,652 Stoker July 20, 1943 2,344,548 Goetz Mar. 21, 1944 2,377,550 Hall June 5, 1945 2,384,660 Ward Sept. 11, 1945 2,490,055 Hoil Dec. 6, 1949 FOREIGN PATENTS Number Country Date 467,019 Great Britain June 9, 1937 OTHER REFERENCES Metal Finishing, February 1944, pages 77 to 79, article entitled Electrotinning Steel Strip at Weirton Steel." 

1. IN APPARATUS FOR PROGRESSIVELY ELECTROLPLATING STRIP, THE COMBINATION COMPRISING, A TANK FOR HOLDING A BATH OF ELECTROPLATING SOLUTION, MEANS FOR MOVING THE STRIP ALONG A HORIZONTAL PATH ACROSS THE TANK FROM THE ENTRY END TO THE EXIT END WHEREBY THE MOVING STRIP DRAGS ELECTROLPLATING SOLUTION IN THE DIRECTION OF STRIP TRAVEL, MEANS FOR SUPPLYING ELECTROPLATING SOLUTION TO THE TANK AN ELECTROPLATING ANODE DISPOSED IN SAID TANK BELOW THE PATH OF THE STRIP, SAID TANK HAVING A BOTTOM WALL, SIDE WALLS EXTENDING UPWARDLY FROM THE BOTTOM WALL, ABOVE THE PATH OF THE STRIP ACROSS THE TANK FOR PREVENTING SPILLAGE OF ELECTROPLATING SOLUTION ACROSS THE SIDE WALLS, AN ENTRY END WALL EXTENDING OF THE STRIP AND TERMINATWALL TOWARD THE PATH OF THE STRIP AND BELOW TERMINATING BELOW THE PATH OF THE STRIP AND BELOW THE SIDE WALLS, SAID TANK BEING FREE OF MEANS PREVENTING THE SPILLAGE OF SOLUTION ACROSS THE TOP OF THE ENTRY END WALL AND SAID ENTRY END WALL FORMING A DISCHARGE WEIR FOR THE SOLUTION AT THE ENTRANCE END OF THE TANK, AND AN EXIT WALL AT THE EXIT END OF THE TANK EXTENDING UPWARDLY FROM THE BOTTOM 